A NEW APPROACH FOR ONE-DIMENSIONAL UNSTEADY FLOW SIMULATION IN NATURAL RIVERS WITH FLOOD PLAINS AND VEGETATION

摘要

Based on the fundamental equations of fluid mechanics a one dimensional unsteady flow model for natural rivers with floodplains is developed. The friction flow, the cross sectional area and the non uniform velocity distribution coefficient are approximated by polynomials as a function of the water depth. The variational integrals of the finite element method are estimated by calculating the derivatives of the integrals analytically and using the Newton-Raphson Method. The model is applied for the tidal stream of the river Stoer in Northern Germany and for a flood at the Danube in Bavaria.